U.S. patent application number 10/090580 was filed with the patent office on 2003-09-11 for ordered liquid crystalline cleansing composition with benefit agent particles.
This patent application is currently assigned to Unilever Home and Personal Care USA, Division of Conopco, Inc.. Invention is credited to Shana'a, May, Villa, Virgilio Barba.
Application Number | 20030171231 10/090580 |
Document ID | / |
Family ID | 27787617 |
Filed Date | 2003-09-11 |
United States Patent
Application |
20030171231 |
Kind Code |
A1 |
Shana'a, May ; et
al. |
September 11, 2003 |
Ordered liquid crystalline cleansing composition with benefit agent
particles
Abstract
An ordered liquid crystalline phase cleansing composition is
disclosed that contains particles with a structure comprising a
benefit agent and a gellation agent and provides high foaming with
in a preferred embodiment levels of free emollient equal to or in
excess of the level of surfactant. A method of depositing a benefit
agent to the skin or hair with the ordered liquid crystalline phase
cleansing composition is also disclosed.
Inventors: |
Shana'a, May; (Trumbull,
CT) ; Villa, Virgilio Barba; (Emerson, NJ) |
Correspondence
Address: |
UNILEVER
PATENT DEPARTMENT
45 RIVER ROAD
EDGEWATER
NJ
07020
US
|
Assignee: |
Unilever Home and Personal Care
USA, Division of Conopco, Inc.
|
Family ID: |
27787617 |
Appl. No.: |
10/090580 |
Filed: |
March 4, 2002 |
Current U.S.
Class: |
510/130 ;
510/159; 510/403; 510/417; 510/418 |
Current CPC
Class: |
A61K 8/0295 20130101;
A61K 8/922 20130101; A61K 8/361 20130101; A61K 8/0241 20130101;
A61K 8/927 20130101; A61K 2800/56 20130101; A61K 8/31 20130101;
A61Q 5/02 20130101; A61K 8/8111 20130101; A61Q 19/10 20130101 |
Class at
Publication: |
510/130 ;
510/159; 510/417; 510/403; 510/418 |
International
Class: |
A61K 007/50; C11D
017/00 |
Claims
We claim:
1. An ordered liquid crystalline phase cleansing composition
comprising: (a) about 3 to about 30% by weight of a surfactant
system including at least one surfactant selected from an anionic,
amphoteric, cationic and nonionic surfactant and mixtures thereof,
wherein at least one anionic surfactant must be present; (b) about
0.1% to about 15% by wt. of an ordered liquid crystalline phase
inducing structurant; (c) about 0.1 to about 25% by weight of
organogel particles of from about 0.05 to about 10 millimeters in
diameter, the particle comprising a benefit agent that is a liquid
at about 75.degree. C. and a gelation agent that is a solid at
about 25.degree. C., the proportions of the gelation agent to
benefit agent being between about 0.05% to about 70% by weight
gelation agent to benefit agent, the solidification or gelation
temperature of the mixture being at or above about 25.degree. C.;
and wherein said ordered liquid crystalline phase composition has a
viscosity of about 40,000 to about 300,000 cps at 25 C.
2. A composition according to claim 1 further comprising about 1%
to about 35% by weight of a free emollient wherein the level of the
emollient is equal to or in excess of the level of surfactant;
3. A composition according to claim 1 further comprising greater
than about 30% by weight water.
4. A composition according to claim 1 wherein the gelation agent
comprises an organic compound selected from a solid organic
compound, a wax, and a polymer.
5. A composition according to claim 1 wherein the benefit agent
comprises an oil that is a liquid at about 25 C.
6. A composition according to claim 1 wherein the benefit agent is
a solid at about 25.degree. C.
7. A composition according to claim 1 wherein the ordered liquid
crystalline phase cleansing composition is a lamellar
composition.
8. A composition according to claim 1 wherein the particle has an
average diameter of between about 0.1 and about 3 millimeters and
the proportions of the gelation agent to benefit agent are between
about 0.5% to about 50% by weight gelation agent to benefit
agent.
9. A composition according to claim 1 wherein the particle has an
average diameter of between about 0.1 and about 1.0 millimeters and
the proportions of the gelation agent to benefit agent are between
about 0.5% to about 40% by weight gelation agent to benefit
agent.
10. A composition according to claim 1 wherein the particle has an
average diameter of between about 0.1 and about 2 millimeters and
the proportions of the gelation agent to benefit agent are between
about 0.5% to about 30% by weight gelation agent to benefit
agent.
11. A composition according to claim 1 wherein the particle is
aspherical.
12. A composition according to claim 1 wherein the gelation agent
forms a network of solid gelation agent within the particles formed
of the benefit agent.
13. A composition according to claim 1 wherein the particle
contains a gradation of concentration of the gelation agent, with
higher concentration of the gelation agent at the surface of the
particles than at the core of the particles.
14. A composition according to claim 1 wherein the surfactant
system is present at a concentration level of at least about 7% by
weight.
15. A composition according to claim 1 wherein the surfactant
system includes a mixture of anionic and amphoteric
surfactants.
16. A composition according to claim 3, wherein the anionic
surfactant is an alkali metal, C8-C16 ether sulfate, and the
amphoteric surfactant is selected from an amphoacetate and an
amidoalkyl betaine.
17. A composition according to claim 1 wherein the ordered liquid
crystalline phase inducing structurant is selected from a C8 to C24
alkenyl or branched alkyl fatty acid or ester thereof, a C8 to C24
alkenyl or branched alkyl alcohol or ether thereof, a C5 to C10
linear alkyl fatty acid, trihydroxystearin, and mixtures
thereof.
18. A composition according to claim 1 wherein the benefit agent is
selected from vegetable oils, esters, animal fats, mineral oil,
petrolatum, silicone oil and mixtures thereof.
19. A composition according to claim 1 further comprising about
0.01 to about 3% by weight of a cationic polymer skin feel agent
selected from cationic polysaccharides, cationic copolymers of
saccharides and synthetic cationic monomers, synthetic cationic
polymers, polymeric quaternary ammonium salts of
hydroxyethylcellulose, cationic proteins, and their salts,
derivatives and mixtures thereof.
20. A composition according to claim 5, wherein the benefit agent
is selected from sunflower seed oil, soybean oil, castor oil,
almond oil, safflower oil, sesame oil, canola oil, jojoba oil olive
oil and mixtures thereof.
21. A composition according to claim 5, wherein the ordered liquid
crystalline phase inducing structurant is selected from lauric
acid, oleic acid, palm kernel acid, palm fatty acid, coconut acid,
isostearic acid, and mixtures thereof.
22. A composition according to claim 1, comprising about 10 to
about 25% surfactant.
23. A method for depositing a benefit agent on to the skin or hair
with an ordered liquid crystalline phase cleansing composition,
said composition comprising: (a) about 3 to about 30% by weight of
a surfactant system including at least one surfactant selected from
an anionic, amphoteric, cationic and nonionic surfactant and
mixtures thereof, wherein at least one anionic surfactant must be
present; (b) about 0.1% to about 15% by wt. of an ordered liquid
crystalline phase inducing structurant; (c) about 0.1 to about 25%
by weight of particles of from about 0.05 to about 10 millimeters
in diameter, the particle comprising a benefit agent that is a
liquid at about 75.degree. C. and a gelation agent that is a solid
at about 25.degree. C., the proportions of the gelation agent to
benefit agent being between about 0.05% to about 70% by weight
gelation agent to benefit agent, the solidification or gelation
temperature of the mixture being at or above about 25.degree. C.;
and wherein said ordered liquid crystalline phase composition has a
viscosity of about 40,000 to about 300,000 cps at 25 C.
24. The method of claim 22 wherein the ordered liquid crystalline
phase cleansing composition is a lamellar composition.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to detergent compositions
suitable for topical application for cleansing the human body, such
as the skin and hair. In particular, it relates to ordered liquid
crystalline phase compositions containing benefit agent
particles.
[0003] 2. Background of the Art
[0004] In order to be acceptable to consumers, a liquid personal
cleansing product must exhibit good cleaning properties, must
exhibit good lathering characteristics, must be mild to the skin
(not cause drying or irritation) and preferably should even provide
a benefit agent to the skin, such as an emollient. Several
approaches have been used to provide high levels of benefit agents
in a stable formula that have involved encapsulating the benefit
agent which is then ruptured or dissolved with product use. For
example, U.S. Pat. No. 5,932,528 to R. Glenn, Jr., et al. issued on
Aug. 3, 1999 discloses a liquid cleansing composition containing a
moisturizing phase comprising an encapsulated lipophilic skin
moisturizing agent and an aqueous cleansing phase comprising a
surfactant and a stabilizer. The encapsulated lipophilic skin
moisturizing agent comprises a lipophilic skin moisturizing agent
encapsulated within a complex coascervate comprising a polycation
and a polyanion.
[0005] Other particles of material including microcapsules,
bubbles, beads, ground particulates, and uniform particulates have
been used in various cleansing and coating applications to
encapsulate or bind the contents of various agents contained
therein or associated therewith. For example U.S. Pat. No.
6,270,836 to Holman issued on Aug. 7, 2001 describes microcapsules
coated with a gel, specifically a gel produced by the sol-gel
process. The gel coating provides certain resistances to the
microcapsules, resulting in enhanced protection for their contents.
Microcapsules containing different types of materials are known
which may be used as ingredients in the compositions of this
invention, such as gelatin.
[0006] It is known that microcapsules may be formed by a
coacervation or crosslinking process, in which lipids are coated by
tiny droplets of proteins, carbohydrates, or synthetic polymers
suspended in water. The process of coacervation is, however,
difficult to control and depends on variables such as temperature,
pH, agitation of the materials, and the inherent variability
introduced by a natural protein or carbohydrate.
[0007] U.S. Pat. No. 6,066,613 to L. Tsaur, et al., issued on May
23, 2000; describes large hydrogel particles suspended in an
aqueous medium and a continuous extrusion/mixing process for making
this kind of hydrogel particles. The hydrogel particles comprise
two different high molecular weight polymers. One is insoluble in
the said aqueous medium and is used for network formation and gel
integrity. The other is soluble in the said aqueous medium and
helps control gel swellability and gel strength. Water insoluble
materials are entrapped or encapsulated inside the network formed
by these two polymers and are able to be more efficiently delivered
from the aqueous composition (e.g., liquid cleanser containing the
hydrogel particles). However there is no disclosure or suggestion
in the prior art of an ordered liquid crystalline cleansing
composition containing organogel particles wherein the particles
are formed by associating benefit agents that are liquids at about
75 C with a gelation agent that is a solid at about 25 C and
wherein said ordered liquid crystalline phase composition has a
viscosity of about 40,000 to about 300,000 cps at 25 C.
BRIEF DESCRIPTION OF THE INVENTION
[0008] In one aspect of the present invention is an ordered liquid
crystalline cleansing composition containing (a) about 3 to about
30% by weight of a surfactant system including at least one
surfactant selected from an anionic, amphoteric, cationic and
nonionic surfactant and mixtures thereof, wherein at least one
anionic surfactant must be present (b) about 0.1% to about 15% by
wt. of an ordered liquid crystalline phase inducing structurant;
(c) about 0.1 to about 25% by weight of organogel particles of from
about 0.05 to about 10 millimeters in diameter, the particle
comprising a benefit agent that is a liquid at about 75.degree. C.
and a gelation agent that is a solid at about 25.degree. C., the
proportions of the gelation agent to benefit agent being between
about 0.05% to about 70% by weight gelation agent to benefit agent,
the solidification or gelation temperature of the mixture being at
or above about 25.degree. C., and wherein said ordered liquid
crystalline phase composition has a viscosity of about 40,000 to
about 300,000 cps at 25 C.
[0009] In another aspect of the invention is a method for
depositing a benefit agent on to the skin or hair with an ordered
liquid crystalline phase cleansing composition, said composition
comprising: (a) about 3 to about 30% by weight of a surfactant
system including at least one surfactant selected from an anionic,
amphoteric, cationic and nonionic surfactant and mixtures thereof,
wherein at least one anionic surfactant must be present; (b) about
0.1% to about 15% by wt. of an ordered liquid crystalline phase
inducing structurant; (c) about 0.1 to about 25% by weight of
particles of from about 0.05 to about 10 millimeters in diameter,
the particle comprising a benefit agent that is a liquid at about
75.degree. C. and a gelation agent that is a solid at about
25.degree. C., the proportions of the gelation agent to benefit
agent being between about 0.05% to about 70% by weight gelation
agent to benefit agent, the solidification or gelation temperature
of the mixture being at or above about 25.degree. C.; and wherein
said ordered liquid crystalline phase composition has a viscosity
of about 40,000 to about 300,000 cps at 25 C.
[0010] Organogel particles suitable for the inventive cleansing
composition comprise a hydrophobic (oleophilic) phase in
particulate form, with no need for a rigid shell to encapsulate the
phase, and usually with no shell present. The particle's oleophilic
phase contains a gelation agent, and preferably an organogelation
agent. Such particles have prolonged stability and can be simply
manufactured. A preferred method of manufacture of the particles
comprises forming a solution of at least the oleophilic material
and gelation agent at a temperature above their gelation
temperature, forming droplets of the solutions, and cooling the
droplets to form particulates. Cooling may be effected by exposure
to ambient conditions (e.g., room temperature) when the ingredients
are appropriately selected with regard to their melting points, or
an actual cooling environment may be needed to form the
particles.
DETAILED DESCRIPTION OF THE INVENTION
[0011] For purposes of the present invention, the following
definitions are used.
[0012] "gel" means a mixture of a solvent and solid material
network (such as a solid network of particle network, fibroid
network, reticulated network, and the like) wherein the solid
material (e.g., any solid such as a waxy material, polymeric
material, sintered or fused particle material, or any other solid
material that forms a physically supportive network for the other
component) is formed through physical aggregation of the solid
material through any associative means. Generally, a gel is more
viscous than a liquid or paste, and retains its shape when left
undisturbed, i.e., is self-supporting. However, a gel is typically
not as hard or firm as a wax. Gels may be penetrated more easily
than a wax-like solid, where "hard" gels are relatively more
resistant to penetration than "soft" gels. A rigid gel as defined
herein resists deformation upon the application of a force.
[0013] "hydrogel" means a gel in which the solvent (diluent) is
water or aqueous based liquids;
[0014] "organogel" means a gel in which the solvent (diluent) is an
organic carrier or organic solvent (as opposed to water or aqueous
based liquids);
[0015] "thermoreversible organogel" is synonymous with "physical
organogel" and means an organogel whose network structure is due to
weak, thermally unstable bonding such as hydrogen bonding (as
opposed to strong, thermally stable bonds such as covalent bonds)
and can, therefore, be heated to a free-flowing, liquid (molten)
state. Upon cooling below a characteristic temperature (T.sub.gel),
the bonds reform and the solid-like gel structure is
re-established.
[0016] T.sub.gel means a temperature at which, by any physical
phenomenon, a mixture of ingredients (e.g., of an oil and organic
material mixed therewith) in discrete form (e.g., particulate,
droplet, drop, pastille, particle, thread, fibroid, etc.) passes
from a flowable or liquid condition into a stable gel or semi-solid
state. Usually this occurs by solidification of gelling or
organization of a liquid material into a more solid form, adding
structure to the discrete form.
[0017] In one aspect of the invention is an ordered liquid
crystalline phase cleansing composition having:
[0018] (a) about 3 to about 30% by weight of a surfactant system
including at least one surfactant selected from an anionic,
amphoteric, cationic and nonionic surfactant and mixtures thereof,
wherein at least one anionic surfactant must be present.
[0019] (b) about 0. 1% to about 15% by wt. of an ordered liquid
crystalline phase inducing structurant;
[0020] (c) about 0.1 to about 25% by weight of organogel particles
of from about 0.05 to about 10 millimeters in diameter, the
particle comprising a benefit agent, preferably an oleophilic
substance that is a liquid at about 75.degree. C. and a gelation
agent that is a solid at about 25.degree. C., the proportions of
the gelation agent to benefit agent being between about 0.05% to
about 70% by weight gelation agent to benefit agent, the
solidification or gelation temperature of the mixture being at or
above about 25.degree. C.
[0021] wherein said ordered liquid crystalline phase composition
has a viscosity of about 40,000 to about 300,000 cps at 25 C.
[0022] Preferably the cleansing composition further includes about
1 to about 35% by weight of an emollient not bound to the particles
(hereinafter "free emollient"). More preferably the cleansing
composition includes about 10 to about 35% by weight of a free
emollient wherein the level of emollient is equal to or in excess
of the level of surfactant. Advantageously the inventive
composition contains at least about 30% by weight water. Preferably
the gelation agent includes an organic compound selected from a
solid organic compound, a wax, and a polymer and the benefit agent
includes an oil that is either a liquid or a solid at about 25 C.
More preferably the cleansing composition includes about 0.1 to
about 10% by wt. of organogel particles.
[0023] Advantageously the particle has an average diameter of
between about 0.1 and about 3 millimeters and the proportions of
the gelation agent to benefit agent are between about 0.5% to about
50% by weight gelation agent to benefit agent. Preferably the
particle has an average diameter of between about 0.1 and about 1.0
millimeters and the proportions of the gelation agent to benefit
agent are between about 0.5% to about 40% by weight gelation agent
to benefit agent. More preferably, the particle has an average
diameter of between about 0.1 and about 2 millimeters and the
proportions of the gelation agent to benefit agent are between
about 0.5% to about 30% by weight gelation agent to benefit
agent.
[0024] Preferably the particle is aspherical, and the gelation
agent forms a network of solid gelation agent within the particles
formed of the benefit agent. Advantageously the particle contains a
gradation of concentration of the gelation agent, with higher
concentration of the gelation agent at the surface of the particles
than at the core of the particles.
[0025] Advantageously the surfactant system is present at a
concentration level of at least about 7% by weight and includes a
mixture of anionic and amphoteric surfactants. Advantageously the
composition includes about 10 to about 25% surfactant. Preferably
the anionic surfactant is an alkali metal, C8-C16 ether sulfate,
and the amphoteric surfactant is selected from an amphoacetate and
an amidoalkyl betaine. Advantageously the ordered liquid
crystalline phase inducing structurant is selected from a C8 to C24
alkenyl or branched alkyl fatty acid or ester thereof, a C8 to C24
alkenyl or branched alkyl alcohol or ether thereof, a C5 to C10
linear alkyl fatty acid, trihydroxystearin, and a mixture thereof,
and the like.
[0026] Preferably the benefit agent is selected from vegetable
oils, esters, animal fats, mineral oil, petrolatum, silicone oil
and mixtures thereof and the like. More preferably the benefit
agent is selected from sunflower seed oil, soybean oil, castor oil,
almond oil, safflower oil, sesame oil, canola oil, jojoba oil and
olive oil. Advantageously the inventive composition includes about
0.01 to about 3% by weight of a cationic polymer skin feel agent
selected from cationic polysaccharides, cationic copolymers of
saccharides and synthetic cationic monomers, synthetic cationic
polymers, polymeric quaternary ammonium salts of
hydroxyethylcellulose, cationic proteins, and salts and derivatives
thereof, and the like.
[0027] The ordered liquid crystalline phase inducing structurant is
preferably selected from lauric acid, oleic acid, palm kernel acid,
palm fatty acid, coconut acid, isostearic acid, and mixtures
thereof.
[0028] In another aspect of the invention is a method for
depositing a benefit agent on to the skin or hair with an ordered
liquid crystalline phase cleansing composition, said composition
comprising:
[0029] (a) about 3 to about 30% by weight of a surfactant system
including at least one surfactant selected from an anionic,
amphoteric, cationic and nonionic surfactant and mixtures thereof,
wherein at least one anionic surfactant must be present;
[0030] (b) about 0.1% to about 15% by wt. of an ordered liquid
crystalline phase inducing structurant;
[0031] (c) about 0.1 to about 25% by weight of particles of from
about 0.05 to about 10 millimeters in diameter, the particle
comprising a benefit agent that is a liquid at about 75.degree. C.
and a gelation agent that is a solid at about 25.degree. C., the
proportions of the gelation agent to benefit agent being between
about 0.05% to about 70% by weight gelation agent to benefit agent,
the solidification or gelation temperature of the mixture being at
or above about 25.degree. C.; and
[0032] wherein said ordered liquid crystalline phase composition
has a viscosity of about 40,000 to about 300,000 cps at 25 C.
[0033] Surfactants:
[0034] Surfactants are an essential component of the inventive
cleansing composition. They are compounds that have hydrophobic and
hydrophilic portions that act to reduce the surface tension of the
aqueous solutions they are dissolved in. Useful surfactants can
include anionic, nonionic, amphoteric, and cationic surfactants,
and blends thereof.
[0035] Anionic Surfactants:
[0036] The cleansing composition of the present invention contains
one or more anionic detergents. The anionic detergent active which
may be used may be aliphatic sulfonates, such as a primary alkane
(e.g., C.sub.8-C.sub.22) sulfonate, primary alkane (e.g.,
C.sub.8-C.sub.22) disulfonate, C.sub.8-C.sub.22 alkene sulfonate,
C.sub.8-C.sub.22 hydroxyalkane sulfonate or alkyl glyceryl ether
sulfonate (AGS); or aromatic sulfonates such as alkyl benzene
sulfonate.
[0037] The anionic may also be an alkyl sulfate (e.g.,
C.sub.12-C.sub.18 alkyl sulfate) or alkyl ether sulfate (including
alkyl glyceryl ether sulfates). Among the alkyl ether sulfates are
those having the formula:
RO(CH.sub.2CH.sub.2O).sub.nSO.sub.3M
[0038] wherein R is an alkyl or alkenyl having 8 to 18 carbons,
preferably 12 to 18 carbons, n has an average value of greater than
1.0, preferably greater than 3; and M is a
[0039] solubilizing cation such as sodium, potassium, ammonium or
substituted ammonium. Ammonium and sodium lauryl ether sulfates are
preferred.
[0040] The anionic may also be alkyl sulfosuccinates (including
mono- and dialkyl, e.g., C.sub.6-C.sub.22 sulfosuccinates); alkyl
and acyl taurates, alkyl and acyl sarcosinates, sulfoacetates,
C.sub.8-C.sub.22 alkyl phosphates and phosphates, alkyl phosphate
esters and alkoxyl alkyl phosphate esters, acyl lactates,
C.sub.8-C.sub.22 monoalkyl succinates and maleates, sulphoacetates,
alkyl glucosides and acyl isethionates, and the like.
[0041] Sulfosuccinates may be monoalkyl sulfosuccinates having the
formula:
R.sup.4O.sub.2CCH.sub.2CH(SO.sub.3M)CO.sub.2M; and
[0042] amide-MEA sulfosuccinates of the formula;
R.sup.4CONHCH.sub.2CH.sub.2O.sub.2CCH.sub.2CH(SO.sub.3M)CO.sub.2M
[0043] wherein R.sup.4 ranges from C.sub.8-C.sub.22 alkyl and M is
a solubilizing cation.
[0044] Sarcosinates are generally indicated by the formula:
R.sup.1CON(CH.sub.3)CH.sub.2CO.sub.2M,
[0045] wherein R.sup.1 ranges from C.sub.8-C.sub.20 alkyl and M is
a solubilizing cation.
[0046] Taurates are generally identified by formula:
R.sup.2CONR.sup.3CH.sub.2CH.sub.2SO.sub.3M
[0047] wherein R.sup.2 ranges from C.sub.8-C.sub.20 alkyl, R.sup.3
ranges from C.sub.1-C.sub.4 alkyl and M is a solubilizing
cation.
[0048] The inventive cleansing composition contains anionic
surfactants, preferably C.sub.8-C.sub.18 acyl isethionates. These
esters are prepared by reaction between alkali metal isethionate
with mixed aliphatic fatty acids having from 6 to 18 carbon atoms
and an iodine value of less than 20. At least 75% of the mixed
fatty acids have from 12 to 18 carbon atoms and up to 25% have from
6 to 10 carbon atoms.
[0049] The acyl isethionate may be an alkoxylated isethionate such
as is described in Ilardi et al., U.S. Pat. No. 5,393,466, titled
"Fatty Acid Esters of Polyalkoxylated isethonic acid; issued Feb.
28, 1995; hereby incorporated by reference. This compound has the
general formula: 1
[0050] wherein R is an alkyl group having 8 to 18 carbons, m is an
integer from 1 to 4, X and Y are hydrogen or an alkyl group having
1 to 4 carbons and M.sup.+ is a monovalent cation such as, for
example, sodium, potassium or ammonium.
[0051] Amphoteric Surfactants
[0052] One or more amphoteric surfactants may be used in this
invention. Such surfactants include at least one acid group. This
may be a carboxylic or a sulphonic acid group. They include
quaternary nitrogen and therefore are quaternary amido acids. They
should generally include an alkyl or alkenyl group of 7 to 18
carbon atoms. They will usually comply with an overall structural
formula: 2
[0053] where R.sup.1 is alkyl or alkenyl of 7 to 18 carbon
atoms;
[0054] R.sup.2 and R.sup.3 are each independently alkyl,
hydroxyalkyl or carboxyalkyl of 1 to 3 carbon atoms;
[0055] n is 2 to 4;
[0056] m is 0 to 1;
[0057] X is alkylene of 1 to 3 carbon atoms optionally substituted
with hydroxyl, and
[0058] Y is --CO.sub.2-- or --SO.sub.3--
[0059] Suitable amphoteric surfactants within the above general
formula include simple betaines of formula: 3
[0060] and amido betaines of formula: 4
[0061] where n is 2 or 3.
[0062] In both formulae R.sup.1, R.sup.2 and R.sup.3 are as defined
previously. R.sup.1 may in particular be a mixture of C.sub.12 and
C.sub.14 alkyl groups derived from coconut oil so that at least
half, preferably at least three quarters of the groups R.sup.1 have
10 to 14 carbon atoms. R.sup.2 and R.sup.3 are preferably
methyl.
[0063] A further possibility is that the amphoteric detergent is a
sulphobetaine of formula: 5
[0064] where m is 2 or 3, or variants of these in which
--(CH.sub.2).sub.3SO.sub.3.sup.- is replaced by 6
[0065] In these formulae R.sup.1, R.sup.2 and R.sup.3 are as
discussed previously.
[0066] Amphoacetates and diamphoacetates are also intended to be
covered in possible zwitterionic and/or amphoteric compounds which
may be used such as e.g., sodium lauroamphoacetate, sodium
cocoamphoacetate, and blends thereof, and the like.
[0067] Nonionic Surfactants
[0068] One or more nonionic surfactants may also be used in the
cleansing composition of the present invention.
[0069] The nonionics which may be used include in particular the
reaction products of compounds having a hydrophobic group and a
reactive hydrogen atom, for example aliphatic alcohols, acids,
amides or alkylphenols with alkylene oxides, especially ethylene
oxide either alone or with propylene oxide. Specific nonionic
detergent compounds are alkyl (C.sub.6-C.sub.22) phenols ethylene
oxide condensates, the condensation products of aliphatic
(C.sub.8-C.sub.18) primary or secondary linear or branched alcohols
with ethylene oxide, and products made by condensation of ethylene
oxide with the reaction products of propylene oxide and
ethylenediamine. Other so-called nonionic detergent compounds
include long chain tertiary amine oxides, long chain tertiary
phosphine oxides and dialkyl sulphoxide, and the like.
[0070] The nonionic may also be a sugar amide, such as a
polysaccharide amide. Specifically, the surfactant may be one of
the lactobionamides described in U.S. Pat. No. 5,389,279 to Au et
al. titled "Compositions Comprising Nonionic Glycolipid Surfactants
issued Feb. 14, 1995; which is hereby incorporated by reference or
it may be one of the sugar amides described in U.S. Pat. No.
5,009,814 to Kelkenberg, titled "Use of N-Poly Hydroxyalkyl Fatty
Acid Amides as Thickening Agents for Liquid Aqueous Surfactant
Systems" issued Apr. 23, 1991; hereby incorporated into the subject
application by reference.
[0071] Cationic Skin Conditioning Agents
[0072] An optional component in compositions according to the
invention is a
[0073] cationic skin feel agent or polymer, such as for example
cationic celluloses. Cationic cellulose is available from Amerchol
Corp. (Edison, N.J., USA) in their Polymer JR (trade mark) and LR
(trade mark) series of polymers, as salts of hydroxyethyl cellulose
reacted with trimethyl ammonium substituted epoxide, referred to in
the industry (CTFA) as Polyquaternium 10. Another type of cationic
cellulose includes the polymeric quaternary ammonium salts of
hydroxyethyl cellulose reacted with lauryl dimethyl
ammonium-substituted epoxide, referred to in the industry (CTFA) as
Polyquaternium 24. These materials are available from Amerchol
Corp. (Edison, N.J., USA) under the tradename Polymer LM-200.
[0074] A particularly suitable type of cationic polysaccharide
polymer that can be used is a cationic guar gum derivative, such as
guar hydroxypropyltrimonium chloride (Commercially available from
Rhone-Poulenc in their JAGUAR trademark series). Examples are
JAGUAR C13S, which has a low degree of substitution of the cationic
groups and high viscosity, JAGUAR C15, having a moderate degree of
substitution and a low viscosity, JAGUAR C17 (high degree of
substitution, high viscosity), JAGUAR C16, which is a
hydroxypropylated cationic guar derivative containing a low level
of substituent groups as well as cationic quaternary ammonium
groups, and JAGUAR 162 which is a high transparency, medium
viscosity guar having a low degree of substitution.
[0075] Particularly preferred cationic polymers are JAGUAR Cl 3S,
JAGUAR C15, JAGUAR C17 and JAGUAR C16 and JAGUAR C162, especially
Jaguar C13S. Other cationic skin feel agents known in the art may
be used provided that they are compatible with the inventive
formulation.
[0076] Cationic Surfactants
[0077] One or more cationic surfactants may also be used in the
cleansing composition.
[0078] Examples of cationic detergents are the quaternary ammonium
compounds such as alkyldimethylammonium halogenides.
[0079] Other suitable surfactants which may be used are described
in U.S. Pat. No. 3,723,325 to Parran Jr. titled "Detergent
Compositions Containing Particle Deposition Enhancing Agents"
issued Mar. 27, 1973; and "Surface Active Agents and Detergents"
(Vol. I & II) by Schwartz, Perry & Berch, both of which are
also incorporated into the subject application by reference.
[0080] In addition, the inventive cleansing composition of the
invention may include 0 to 15% by wt. optional ingredients as
follows: perfumes; sequestering agents, such as tetrasodium
ethylenediaminetetraacetate (EDTA), EHDP or mixtures in an amount
of 0.01 to 1%, preferably 0.01 to 0.05%; and coloring agents,
opacifiers and pearlizers such as zinc stearate, magnesium
stearate, TiO.sub.2, EGMS (ethylene glycol monostearate) or Lytron
621 (Styrene/Acrylate copolymer) and the like; all of which are
useful in enhancing the appearance or cosmetic properties of the
product.
[0081] The compositions may further comprise antimicrobials such as
2-hydroxy-4,2', 4' trichlorodiphenylether (DP300); preservatives
such as dimethyloldimethylhydantoin (Glydant XL1000), parabens,
sorbic acid etc., and the like.
[0082] The compositions may also comprise coconut acyl mono- or
diethanol amides as suds boosters, and strongly ionizing salts such
as sodium chloride and sodium sulfate may also be used to
advantage.
[0083] Antioxidants such as, for example, butylated hydroxytoluene
(BHT) and the like may be used advantageously in amounts of about
0.01% or higher if appropriate.
[0084] Humectants such as polyhydric alcohols, e.g. glycerine and
propylene glycol, and the like; and polyols such as the
polyethylene glycols listed below and the like may be used.
1 Polyox WSR-205 PEG 14M, Polyox WSR-N-60K PEG 45M, or Polyox
WSR-N-750 PEG 7M.
[0085] The benefit agent and free emollient may be the same or
different. Furthermore the benefit agent or the free emollient or
both may be a mixture of two or more compounds one or all of which
may have a beneficial aspect. In addition, the benefit agent and
free emollient may separately or together act as a carrier for
other components one may wish to add to the cleansing
composition.
[0086] A blend of a hydrophobic and hydrophilic emollients may be
used. Preferably, hydrophobic emollients are used in excess of
hydrophilic emollients in the inventive cleansing composition. Most
preferably one or more hydrophobic emollients are used alone.
Hydrophobic emollients are preferably present in a concentration
greater than about 10% by weight, more preferably about 12% by
weight. The term "emollient" is defined as a substance which
softens or improves the elasticity, appearance, and youthfulness of
the skin (stratum corneum) by either increasing its water content,
adding, or replacing lipids and other skin nutrients; or both, and
keeps it soft by retarding the decrease of its water content.
[0087] Useful emollients include the following:
[0088] (a) silicone oils and modifications thereof such as linear
and cyclic polydimethylsiloxanes; amino, alkyl, alkylaryl, and aryl
silicone oils;
[0089] (b) fats and oils including natural fats and oils such as
jojoba, soybean, sunflower, rice bran, avocado, almond, olive,
sesame, persic, castor, coconut, mink oils; cacao fat; beef tallow,
lard; hardened oils obtained by hydrogenating the aforementioned
oils; and synthetic mono, di and triglycerides such as myristic
acid glyceride and 2-ethylhexanoic acid glyceride;
[0090] (c) waxes such as carnauba, spermaceti, beeswax, lanolin,
and derivatives thereof;
[0091] (d) hydrophobic and hydrophillic plant extracts;
[0092] (e) hydrocarbons such as liquid paraffins, vaseline,
microcrystalline wax, ceresin, squalene, pristan and mineral
oil;
[0093] (f) higher fatty acids such as lauric, myristic, palmitic,
stearic, behenic, oleic, linoleic, linolenic, lanolic, isostearic,
arachidonic and poly unsaturated fatty acids (PUFA);
[0094] (g) higher alcohols such as lauryl, cetyl, stearyl, oleyl,
behenyl, cholesterol and 2-hexydecanol alcohol;
[0095] (h) esters such as cetyl octanoate, myristyl lactate, cetyl
lactate, isopropyl myristate, myristyl myristate, isopropyl
palmitate, isopropyl adipate, butyl stearate, decyl oleate,
cholesterol isostearate, glycerol monostearate, glycerol
distearate, glycerol tristearate, alkyl lactate, alkyl citrate and
alkyl tartrate;
[0096] (i) essential oils and extracts thereof such as mentha,
jasmine, camphor, white cedar, bitter orange peel, ryu, turpentine,
cinnamon, bergamot, citrus unshiu, calamus, pine, lavender, bay,
clove, hiba, eucalyptus, lemon, starflower, thyme, peppermint,
rose, sage, sesame, ginger, basil, juniper, lemon grass, rosemary,
rosewood, avocado, grape, grapeseed, myrrh, cucumber, watercress,
calendula, elder flower, geranium, linden blossom, amaranth,
seaweed, ginko, ginseng, carrot, guarana, tea tree, jojoba,
comfrey, oatmeal, cocoa, neroli, vanilla, green tea, penny royal,
aloe vera, menthol, cineole, eugenol, citral, citronelle, borneol,
linalool, geraniol, evening primrose, camphor, thymol, spirantol,
penene, limonene and terpenoid oils;
[0097] (j) lipids such as cholesterol, ceramides, sucrose esters
and pseudo-ceramides as described in European Patent Specification
No. 556,957;
[0098] (k) vitamins, minerals, and skin nutrients such as milk,
vitamins A, E, and K; vitamin alkyl esters, including vitamin C
alkyl esters; magnesium, calcium, copper, zinc and other metallic
components;
[0099] (l) sunscreens such as octyl methoxyl cinnamate (Parsol MCX)
and butyl methoxy benzoylmethane (Parsol 1789);
[0100] (m) phospholipids;
[0101] (n) antiaging compounds such as alpha hydroxy acids, beta
hydroxy acids; and
[0102] (o) mixtures of any of the foregoing components, and the
like.
[0103] Preferred benefit agents and free emollients are selected
from triglyceride oils, mineral oils, petrolatum, and mixtures
thereof. Further preferred benefit agents and free emollients are
triglycerides such as sunflower seed oil.
[0104] Ordered Liquid Crystalline Compositions:
[0105] The inventive cleansing composition possesses ordered liquid
crystalline microstructure, preferably lamellar microstructure
structure. The Theological behavior of all surfactant solutions,
including liquid cleansing solutions, is strongly dependent on the
microstructure, i.e., the shape and concentration of micelles or
other self-assembled structures in solution.
[0106] When there is sufficient surfactant to form micelles
(concentrations above the critical micelle concentration or CMC),
for example, spherical, cylindrical (rod-like or discoidal),
spherocylindrical or ellipsoidal micelles may form. As surfactant
concentration increases, ordered liquid crystalline phases such as
lamellar phase, hexagonal phase, cubic phase or L3 sponge phase may
form. The lamellar phase, for example, consists of alternating
surfactant bilayers and water layers. These layers are not
generally flat but fold to form submicron spherical onion like
structures called vesicles or liposomes. The hexagonal phase, on
the other hand, consists of long cylindrical micelles arranged in a
hexagonal lattice. In general, the microstructure of most personal
care products consist of either spherical micelles; rod micelles;
or a lamellar dispersion.
[0107] As noted above, micelles may be spherical or rod-like.
Formulations having spherical micelles tend to have a low viscosity
and exhibit Newtonian shear behavior (i.e., viscosity stays
constant as a function of shear rate; thus, if easy pouring of
product is desired, the solution is less viscous and, as a
consequence, it doesn't suspend as well). In these systems, the
viscosity increases linearly with surfactant concentration.
[0108] Rod micellar solutions are more viscous because movement of
the longer micelles is restricted. At a critical shear rate, the
micelles align and the solution becomes shear thinning. Addition of
salts increases the size of the rod micelles thereof increasing
zero shear viscosity (i.e., viscosity when sitting in bottle) which
helps suspend particles but also increases critical shear rate
(point at which product becomes shear thinning; higher critical
shear rates means product is more difficult to pour).
[0109] Lamellar dispersions differ from both spherical and rod-like
micelles because they can have high zero shear viscosity (because
of the close packed arrangement of constituent lamellar droplets),
yet these solutions are very shear thinning (readily dispense on
pouring). That is, the solutions can become thinner than rod
micellar solutions at moderate shear rates.
[0110] In formulating liquid cleansing compositions, therefore,
there is the choice of using rod-micellar solutions (whose zero
shear viscosity, e.g., suspending ability, is not very good and/or
are not very shear thinning); or lamellar dispersions (with higher
zero shear viscosity, e.g. better suspending, and yet are very
shear thinning). Such lamellar compositions are characterized by
high zero shear viscosity (good for suspending and/or structuring)
while simultaneously being very shear thinning such that they
readily dispense in pouring. Such compositions possess a "heaping",
lotion-like appearance which convey signals of enhanced
moisturization.
[0111] When rod-micellar solutions are used, they also often
require the use of external structurants to enhance viscosity and
to suspend particles (again, because they have lower zero shear
viscosity than lamellar phase solutions). For this, carbomers and
clays are often used. At higher shear rates (as in product
dispensing, application of product to body, or rubbing with hands),
since the rod-micellar solutions are less shear thinning, the
viscosity of the solution stays high and the product can be stringy
and thick. Lamellar dispersion based products, having higher zero
shear viscosity, can more readily suspend emollients and are
typically more creamy. In general, lamellar phase compositions are
easy to identify by their characteristic focal conic shape and oily
streak texture while hexagonal phase exhibits angular fan-like
texture. In contrast, micellar phases are optically isotropic.
[0112] It should be understood that lamellar phases may be formed
in a wide variety of surfactant systems using a wide variety of
lamellar phase "inducers" as described, for example, in U.S. Pat.
No. 5,952,286 issued to Puvvada, et al., on Sep., 14, 1999.
Generally, the transition from micelle to lamellar phase are
functions of effective average area of headgroup of the surfactant,
the length of the extended tail, and the volume of tail. Using
branched surfactants or surfactants with smaller headgroups or
bulky tails are also effective ways of inducing transitions from
rod micellar to lamellar.
[0113] One way of characterizing ordered liquid crystalline
dispersions include measuring viscosity at low shear rate (using
for example a Stress Rheometer) when additional inducer (e.g.,
oleic acid or isostearic acid) is used. At higher amounts of
inducer, the low shear viscosity will significantly increase.
[0114] Another way of measuring ordered liquid crystalline
dispersions is using freeze fracture electron microscopy.
Micrographs generally will show ordered liquid crystalline
microstructure and close packed organization of the lamellar
droplets (generally in size range of about 2 microns).
[0115] The inventive ordered liquid crystalline-isotropic
composition preferably has a low shear viscosity in the range of
about 40,000 to about 300,000 centipoises (cps) measured at 0.5 RPM
using T-bar spindle A using the procedure described below. More
preferably the viscosity range is about 50,000 to about 150,000
cps.
[0116] Organogels
[0117] A stable particle suitable for the inventive composition of
from 0.05 to 2, 5 or 10 millimeters in diameter comprises a mixture
of a benefit agent that is an oleophilic liquid at 25.degree. C.,
50.degree. C., or 75.degree. C. and a gelation agent or
organogelation agent, the proportions of the gelation agent to
oleophilic liquid being between 0.05% to 70%, or 0.05% to 50%, or
0.05% to 30% by weight gelation agent to oleophilic liquid, the
T.sub.gel of the mixture being above 25.degree. C. The gelation
agent may comprise an organogelation agent, which is a term
understood in the art and further defined herein. The particle may
provide the oleophilic material liquid (or solid) as an oil, oil
mixture, oil dispersion or suspension, or oil solution. A group of
particles may have an average diameter of between 0.05 to 10
millimeters, between 0.08 and 10 millimeters, between 0.08 and 5
millimeters, between 0.1 and 5 millimeters, between 0.1 and 2
millimeters, and 0.1 and 1 millimeters and the proportions of the
gelation agent to oleophilic liquid may be, for example, between
0.5% to 20% or more by weight gelation agent to oleophilic
liquid.
[0118] The T.sub.gel of the mixture or the T.sub.gel of the
individual components forming the organogel particle refers to the
temperature at which the composition gels from an essentially
liquid state as the temperature drops, or the temperature at which
an individual component gels when the temperature of a liquid
component is dropped.
[0119] A preferred method of forming such a stable organogel
particle may include:
[0120] a) mixing together at least the oleophilic liquid and the
gelation agent,
[0121] b) providing the mixture as a fluid material (having liquid
or flowable properties), the mixture being at a temperature at
least 5.degree. C. above the solidifying temperature, such as at
least 5.degree. C. above the T.sub.gel of the mixture and/or the
gelation agent;
[0122] c) forming discrete elements, such as droplets, pastilles,
strands, particles, shapes, or other solid accumulations or gels of
the material (preferably a fluid material); and
[0123] d) cooling the solid accumulation (e.g., droplets, strands,
particles, shapes, etc.) to a temperature at or at least 5.degree.
C. below the solidification temperature of the gelation agent of
the T.sub.gel of the mixture or gelation agent or at any other
temperature that causes gelation to form solid, relatively stable
particles.
[0124] Organogel particle hardness is an important parameter in
formulating an acceptable cleansing composition. Typically the
hardness is advantageously adjusted to be satisfactory to the user
and can be defined as the Particle Breakage Index (PBI) or the
amount of force (weight) required to break or rupture the particle.
PBI is conveniently expressed in terms of grams per square
millimeter and is calculated based on the following equation:
PBI=weight need to break a particle (g)/cross section area of
particle (mm.sup.2.)
[0125] Preferably, the particles should have a PBI value of about
0.05 up to 10, more preferably about 0.5 to about 5 and most
preferably about 1.5 to 3.0. Such properties correspond to what the
average user of the inventive cleansing composition considers as
highly acceptable hardness for the particles. The strength can be
controlled by the exercise of reasonable judgment and selection of
ingredients and proportions according to art recognized techniques.
Viscosity agents, thixotropic agents, surfactants, solid binders,
antistatic agents, crosslinking agents, coupling agents, dispersing
agents, emulsifying agents, thinning agents, and the like are among
the types of additives that can be added in amounts between 0.001
and 30% by weight of the hydrophobic (oleophilic) material (e.g.,
the oil) to assist in the control of the properties of the
organogel particles, such as size, physical strength, durability,
and the like.
[0126] With respect to particle gel rheology, typically, gels
possess a storage modulus G'(w) which exhibits a pronounced plateau
at higher frequencies (on the order of 1-100 radians/second), and a
loss modulus G"(w) which is considerably smaller than the storage
modulus in the plateau region. In a strict sense, the term "gel"
applies to systems having a value G'(w) that is higher than its
value of G"(w) at low frequencies. Many of the compositions
according to the present invention are gels by one or both of the
above definitions. A gel is free-standing or self-supporting in
that its yield value is greater than the shear stress imposed by
gravity.
[0127] Rheological parameters such as the storage modulus G'(w) can
be measured as a function of angular frequency with a
parallel-plate rheometer. For example, such parameters can be
generated using a Rheometrics Dynamic Analyzer Model 70, using a
0.5 cm stainless steel plate and a 2.3 mm sample gap, over a
temperature sweep of 25-85.degree. C. at 1% strain and 6.3
radians/sec. Characterization of the rheological behavior of a
gelled body according to the present invention can be made using
the Rheometrics instrument and conditions set forth above. As the
gel is heated, it retains significant gel-like character until its
Tgel temperature is reached. The viscosity of the particles at room
temperature may typically vary from 10 to a few thousand cP or
higher, even to the point of approaching properties that appear
more solid than gel like.
[0128] Another property that may be directly measured is shear
viscosity at e.g. 0.1 rad/sec as measured by ASTM D 2765-Procedure
A. The shear viscosity, for example, may range from at least about
5 percent higher compared with the oil at room temperature to
orders of magnitude higher than the shear viscosity at room
temperature of the oils as measured by ASTM D 2765-Procedure A.
[0129] The precise process and phenomena that contribute to the
formation of the particles, and the precise structure of the
particles may vary between different combinations of materials, and
even between different proportions of the same materials. It is
believed that at least one of the following three systems and
processes occur during the practice of the present invention,
although these descriptions and/or hypothesis are not intended to
be limiting on the scope of actual processes and structures that
are provided in the practice of the present invention. The first
method is where the two organic materials (the oleophilic agent and
the gelation agent) are provided as a mixture at a temperature at
which both materials are together as a fluid (e.g., preferably as a
true liquid, but at least in a form that is flowable and in which
the at least two ingredients are intimately mixed). This
temperature usually requires that the softening temperature and/or
the flow temperature or melt temperature (e.g., T.sub.g1 and/or
T.sub.g2) be exceeded. After the fluid and the intermixed
components have been provided at this elevated temperature (e.g.,
at a temperature above 25.degree. C., above 40.degree. C., above
50.degree. C., above 60.degree. C., above 75.degree. C., above
85.degree. C., above 100.degree. C., above 120.degree. C., above
150.degree. C., above 175.degree. C., and the like, up to
temperatures short of where the individual components boil or
decompose), the composition is cooled. The cooling temperature,
depending upon how low a temperature to which the mixture is
dropped, will cause at least one or both of the at least two
ingredients to solidify. This cooling is done while the mixture is
in or being placed into particulate form, as by prilling,
pastilling, spray drying (or spray cooling in this case), or any
other particle forming process. Because the at least two materials
are intermixed, as opposed to the encapsulating relationship found
in prior art microencapsulation processes, as the first or both at
least two materials (the oleophilic agent and the gelation agent)
harden or solidify, they remain intermixed. It is particularly at
this point that the nature of the particle forming phenomenon
becomes alternative in nature. The gelation agent, in some
circumstances is believed to form fibroids, tendrils, fibers,
reticulated structures, aspherical shapes, elongate elements or the
like (e.g., with aspect ratios of at least 3, aspect ratios of at
least 4 or 5, and higher, up to continuous filamentary elements
with extremely high aspect ratios) within the particle material
(e.g., within a droplet). These various structural elements form a
physical support for the oleophilic material, whether supporting
the oleophilic material by surface tension to the solid, adsorption
to the solid, partial entrapment by the solid, entrapment by the
solid, partial absorption by the solid, or by any other physical or
physical chemical means by which the solid material supports and
maintains a particulate shape for the at least two materials. A
second method of stable particle, or droplet formation may occur
where the structural elements may even be particulates without
elongate structure (e.g., aspect ratios between 1 and 3, or between
1 and 5), wherein the physical forces between the particles and the
oleophilic agent sustains the particle, or droplet structure. The
particles may or may not be in contact with each other and may or
may not be bound by physical or chemical means to each other during
the gelation or solidifying process, but they do provide actual
support for the particle, or droplet structure so that the product
exists as a stable particle. A third method by which particle
stabilization or gelation may occur is with the formation of a
gradation of materials within the particle, with the highest
concentration of the gelation agent at the surface of the droplet
and the least concentration of the gelation agent (yet still above
0.0) occurring at center of the particle. This is not traditional
encapsulation or microencapsulation where there is a clear
distinction and sharp separation between a shell (solid) and a core
(liquid). The gradation may have the outermost surface of the
particle as 100% gelation material (and entrapped solids or
intended diluents or active ingredients), but may also have 99%,
95%, 90%, 80%, 75%, 50%, 40%, 35% 30% or the like of gelation agent
in the outermost surface and lower amounts within the body of the
particle, the remainder of the concentration being provided as the
oleophilic material and its associated components.
[0130] As noted above and later herein, a preferred aspect of the
invention uses a gelation agent that is a solid at 25.degree. C. to
stabilize an oleophilic fluid, flowable or liquid material. The
oleophilic material may also be a solid or difficult to flow
material at 25.degree. C., so that the particle may even be a solid
oleophilic material in a solid matrix or network of solid
supporting elements or gelation agent. The solid network of
gelation agent may have provided structural support for the
oleophilic material during the solidification process and remains
as a network after the cooling of the oleophilic material to a
solid. The final stable particle may therefore be a support system
of the gelation agent and a liquid or semisolid or solid oleophilic
material; in particle form. It must be noted again, that the term
particle generically refers to a bead, pastille, solid droplet,
fibroid, sphere, oblong, filamentary object, reticulated network,
or other solid form with the required maximum diameter of 10 mm or
less. The average diameter may be based upon number average
diameter or any other basis as desired.
[0131] According to the present invention, molten (liquid)
organogels are formed into any solid accumulation of materials such
as droplets, particles, pastilles, strands, fibroids, from liquids
provided above their gelation temperatures (T.sub.gel). As is
understood in the art, the T.sub.gel is the temperature at which
gel-to-sol transition occurs. It is preferred that the T.sub.gel of
the molten compositions be about between 20.degree. C. and
70.degree. C. when used to form the solid accumulations in forming
the particles or the invention. It is also preferred that the
molten coating compositions be coated from about 5C.degree. to
25C.degree. above the T.sub.gel of the composition.
[0132] The particle-forming compositions of the invention may also
form thermoreversible gels, although any type of gel formation may
be used. Generally, a thermoreversible organogel is characterized
by the observation of a T.sub.gel. The T.sub.gel may be determined
by several different criteria, such as, for example, the
temperature at which: (a) when a liquid composition is cooled,
there is a rapid, discrete, qualitative change from liquid to solid
properties; (b) when a liquid composition is cooled, there is a
sudden increase in hydrodynamic radius, as measured by dynamic
light scattering methods; (c) when a liquid composition is warmed,
a 1 mm drop of mercury will flow through the composition; and (d)
the elastic and viscous moduli are equivalent.
[0133] As noted above, the particles (which term is used to
generically encompass the particles of the invention, whether they
are beads, strands, particles, shapes, fibroids, filamentary
shapes, pastilles or any other solid accumulation) are formed from
two distinct materials that may be present as two distinct phases.
The two distinct materials comprise what are referred to in the
practice of the invention as the organic solid network, and the
other component is referred to as the oleophilic liquid, oleophilic
material or generally as the oleophilic organic medium. It may be
difficult at times to distinguish which material is apparently
working at the various function because of the dimensions and
intimacy of the materials. For example, two phase or multiphase
systems may form, or what is generally referred to as
interpenetrating networks, where the functions of the materials,
particularly where both materials may be present as solids, cannot
clearly be defined or distinguished as a supporting, carrier, or
supported phase. Even where a solid organic network is supporting a
liquid organic medium, chilling the particle so that the liquid
organic medium solidifies does not remove the particle from the
practice of the invention. The gelation agent or organic solid
network may be any organic material that passes from liquid to
solid state during the cooling process and with its solid structure
supports the other organic medium. The organic solid medium may
comprise organic materials that are solids at the cool-down
temperature, organic or inorganic waxes, polymers, copolymers,
oligomers, and the like. The term gelation is used, rather than
some other term, because the process appears to act in the manner
of a gel-forming process, and many of the particles appear to act
as gels, rather than solid particles.
[0134] The nature of some of the compositions, such as those that
can be defined according to standards in the art as
thermoreversible gels, are clearly gel and gelation compositions.
Non-limiting examples of liquid compositions that form
thermoreversible organogels at or near room temperature include
nitrocellulose in ethyl alcohol, and the like. Although not wishing
to be bound by theory, Applicants postulate that thermoreversible
organogels suitable for use in the present invention may contain a
polymer or copolymer wherein the polymer or copolymer chain
contains two or more different functional groups or discrete
regions, e.g., syndiotactic sequences prone to crystallite
formation in a solvent or solvent mixture. It is believed that the
addition of an alcohol to a polymer capable of hydrogen bonding
prevents or reverses gel formation because of the hydrogen bonding
of alcohol-based solvents with polymer sites capable of hydrogen
bonding. The requirements of the solvent blend are that it must not
interact with polymer hydrogen bonding sites along the polymer
chain and thereby interfere with the polymeric binder's ability to
undergo hydrogen bonding with itself through the such sites, yet it
must solvate the polymer at the non-hydrogen bonding sites and be
an overall solvent for the polymer at temperatures above T.sub.gel.
A further requirement is that upon cooling below T.sub.gel the
polymer remains in solution forming a gel that is a homogeneous,
clear, solid solution as opposed to forming an opaque heterogeneous
mass.
[0135] In using molten thermoreversible organogel solutions, it is
necessary to form the particles at temperatures above the T.sub.gel
of the organogel. On the other hand, it is desirable to perform the
processing at the lowest possible temperature above T.sub.gel in
order to facilitate rapid onset of gelation after forming. It has
been found advantageous to provide a "chill-box" or similar rapid
chilling mechanism which functions immediately after the forming
operation to trigger rapid gelation to inhibit interlayer mixing.
Preferably, the molten organogel temperatures during forming should
be 5C.degree. to 25C.degree. above T.sub.gel. More preferably, the
molten organogel temperatures during coating should be from about
10C.degree. to about 15C.degree. above T.sub.gel.
[0136] The coating solutions or dispersions are solidified
organogels at or near room temperature and liquids at a modestly
elevated temperature. The solutions are warmed to 5C.degree. to
25C.degree. above their T.sub.gel so that they are liquids. The
molten solutions are spray dried, prilled, pastilled, dispersion
solidified, drip-dried, spray extruded, or as known by those of
ordinary skill in the art to be otherwise formed into a solid
particle by being cooled below their gel temperature while in
particulate or droplet form.
[0137] The term "PLURONICTM" refers to poloxamer compounds useful
as gelation agents and which are sold collectively under the
trademark PLURONIC.TM. (BASF, Parsippany, N.J.). PLURONIC F-127 (PL
127) corresponds to poloxamer 407, a
polyoxypropylene-polyoxyethylene block copolymer described by
Schmolka in the Journal of Biomedical Materials Research 6:571-582,
1972. Other PLURONIC.TM. compounds may be used in the present
invention. As used in this application, the terms PLURONIC.TM.
organogel, poloxamer organogel, and
polyoxyethylene/polyoxypropylene organogel are synonymous.
[0138] Other non-limiting examples of gelation materials include
waxes (e.g., beeswax, paraffin, water-insoluble wax, carbon-based
wax, silicone wax, microcrystalline wax, etc.), triglycerides, acid
triglycerides, polymers, fluoroalkyl (meth)acrylate polymers and
copolymers, acrylate polymers, ethylene/acrylate copolymers,
polyethylene, polypropylene polymers and copolymers, fatty acids,
fatty alcohols, fatty acid esters, fatty acid ethers, fatty acid
amides, alkylene polyhydric alcohols, fatty acid amide of an
alkanolamine, glyceryl monostearate, (aryl-substituted)sugars,
dibenzyl sorbitol (or mannitoal, rabbitol, etc.), condensates and
precondensates of lower monohydric alcohols, trihydroic alcohols,
lower polyglycols, propylene/ethylene polycondensates, and the
like.
[0139] The benefit agent or oleophilic material may be any
oleophilic material, whether a single pure compound, a solution, a
composition, a mixture, an emulsion (e.g., an oil-in-water emulsion
or preferably a water-in-oil emulsion), a dispersion, or the like.
Among the many types of oleophilic materials useful in the
inventive composition may be included oils, essential oils,
emollients (as described above), antimicrobial agents, medications,
exfoliating agents, fragrances, cosmetics, astringents, colorants,
antioxidants, enzymes, sunscreens or ultraviolet radiation
absorbing compositions, and the like. As noted the general range,
when considering two phases, ranges from about 0.5% to 70% by
weight of gelation agent and from 70 to 99.5% by weight liquid
oleophilic composition. Alternative ranges of the gelation agent
are from 1-60%, 1-50%, 1-30%, 2-25%, 5-25%, 7-25%, 10-25%, and
12-20% by total weight of the particle or by weight of the
hydrophobic liquid. At the higher levels of gelation agent (e.g.,
from 12%-30%, greater than 15%, and from 15-30% by weight), the
particles tend to be gelled more firmly, and are very stable,
[0140] Benefit agents may be pure, raw, may contain dispersed
materials or may have suspended or dispersed materials added to the
benefit agent. For example, abrasive particles may be suspended to
provide scrubbing or exfollient effects, silica, titania, calcium
carbonate, talc, starch, pigments, conductive particles, reflective
particles, frangible particles, reactive materials, moisture
sensitive particles (e.g., urea particles, zeolites, gas-generating
particles), and the like. Other forms of active or assistive
ingredients are described elsewhere. The concentration of such
materials may be from 0%, 0.001% to 20% or 40% of the hydrophobic
component.
[0141] Various other ingredients, some of which have been noted
above, may also be included within the solution prior to being
formed into droplets. Such additional ingredients include (a) a wax
or wax mixture of about 1 part by weight mineral ester wax having
an acid value of about 0 to about 55, about 4 parts by weight
partly saponified mineral ester wax having an acid value of about
10 to about 45, about 1.5 parts by weight insect wax having an acid
value of about 0.2 to about 24; (b) a film-forming agent that is a
curable material selected from the group consisting of a curable
emulsion polymer, a curable resin, a curable aminofunctional
silicone, and mixtures thereof; (c) a film-modifying agent that is
a surfactant selected from the group consisting of a surface-active
aminofunctional silicone, a linear arylalkyl modified polydialkyl
siloxane, a linear alkylated copolymer of vinylpyrrolidone with a
long chain (C.sub.12 to C.sub.22) alpha olefin, and mixtures
thereof; (d) a nonionic emulsifying agent having an HLB* value of
about 10 to about 15 and, for example, selected from the group
consisting of an oil-soluble polyglycerol ester of a hydrophobic
fatty acid capable of forming a water in oil emulsion, a
water-soluble C.sub.8 to C.sub.18 alkylphenol ether with ethylene
oxide having an average number of ethylene oxide units of of about
5 to about 70, and mixtures thereof (*HLB-hydrophile-lipophile
balance); (e) an effective amount of an anionic oleophilic
dispersing agent; (f) a thickening agent selected from the group
consisting of polymers, colloids, alkaline earth metal aluminum
silicate, non-ionic, cationic or anionic esters, and mixtures
thereof; (g) an organic solvent selected from the group consisting
of a liquid aliphatic hydrocarbon, a liquid aromatic hydrocarbon,
and an oleoresinous liquid having an average kauri-butanol value
above 50, and mixtures thereof; and (h) an effective amount of a
preservative.
[0142] The properties of the particles may be controlled by various
disciplines and additives as desired. The size can be controlled by
the size of spray heads, the degree of shearing forces, the
temperatures of the initial gel solution, the gelation rate, the
viscosity of the gel composition, and other physical
mechanisms.
[0143] The invention will now be described in greater detail by way
of the following non-limiting examples. The examples are for
illustrative purposes only and not intended to limit the invention
in any way.
[0144] Except in the examples, or where otherwise explicitly
indicated, all numbers in this description indicating amounts or
ratios of materials or conditions or reaction, physical properties
of materials and/or use are to be understood as modified by the
word "about".
[0145] Where used in the specification, the term "comprising" is
intended to include the presence of stated features, integers,
steps, components, but not to preclude the presence or addition of
one or more features, integers, steps, components or groups
thereof.
[0146] All percentages in the specification and examples are
intended to be by weight unless stated otherwise.
EXAMPLE 1
[0147] The following components were used to form an organogel
particle suitable for the inventive cleansing composition.
2 Sunflower oil 89.5% Polywax .RTM. 500 10.0% Pigment 0.5% (Sun
Chemical D&C Red #6 BA Lake)
[0148] This formulation was combined and melted in a flask. The
melted composition was then subsequently prilled into a water catch
tank using a single fluid nozzle. Three different sized nozzles
were used to produce particles that were approximately 600 to 800
microns, 800 to 1200 microns, and 1000 to 1400 microns.
[0149] The above particles of the size 800 to 1200 microns were
placed in a gel consisting of: water, Vitamin E in SD alcohol 40,
glycerin, polysorbate 20, aloe barbadensis gel, carbomer,
triethenolamine, methyl paraben, imidazolidinyl urea, fragrance,
Vitamin A palmitate, tea tree oil, colorants.
EXAMPLE 2
[0150] The following components were used to form an organogel
particle suitable for use with the inventive cleansing
composition.
[0151] Sunflower oil 80.9%
[0152] Fragrance oil 9.3
[0153] Intercontinental Fragrances Cinnamon Concentrate FG#8673
[0154] Polywax.RTM. 500 9.8
[0155] These ingredients were melted together and made into
pastilles by depositing pasty droplets of materials onto a release
surface and drying the droplets.
EXAMPLE 3
[0156] The following components were used to form an organogel
particle suitable for use with the inventive cleansing composition.
The firmness of sunflower oil gelled with 10% Polywax.RTM. 500 was
compared with the firmness of sunflower oil gelled with 10%
beeswax. It was found that the sunflower oil gelled with
Polywax.RTM. 500 was firmer than sunflower oil gelled with
beeswax.
EXAMPLE 4
[0157] The following kinds of organogel particles (a) to (f)
suitable for use with the inventive cleansing composition were
made:
3 (a) Sunflower oil 70% Beeswax 30% (b) Sunflower oil 70% Carnauba
wax 30% (c) Polywax .RTM. 2000 10% Sunflower oil 90% (d) Koster
Kuenen Synthetic Paraffin Wax #201 5% Sunflower oil 95% (e) Polywax
.RTM. 500 10% Mineral Oil 90% (f) 90% AC Humko Cottonseed Flakes
F05030 10% Polywax .RTM. 1000 Blends (a) to (f) were separately
melted and formed into pastilles.
EXAMPLE 5
[0158] The degree of softness and spreadablility as perceived with
use of various inventive organogel particles was assessed according
to test methods described below and the results are summarized in
table 1.
4TABLE 1 Particle Composition Particle Attributes Sunflower to
Degree of Polywax Ratio Softness Ease of Spread 80:20 Very Hard
Unacceptable 85:15 Hard Unacceptable 90:10 Just Right Highly
Acceptable 94:6 Soft Slightly Acceptable
EXAMPLE 6
[0159] Lamellar cleansing compositions I, II, and III were
formulated as listed in table 1 and were evaluated for organogel
particle stability and particle hardness:
[0160] Composition I was prepared by combining Sodium
Lauroamphoacetate and Sodium Laureth Sulfate in a vessel, mixed and
simultaneously heated to about 80 C until a clear solution was
formed. Then Sodium Cocoyl Isethionate prills were mixed with the
above surfactant solutions until dissolved completely, then
opacifier, polymers citric acid and water were added to mixture. At
this point, Cocamidopropyl Betaine was added to quench the mixture.
The blend was then cooled down and during the cooling process,
Dimethicone and preservatives were added. At about 40 C, isostearic
acid was added to complete the structuring of the mix. When the
temperature reached about 35 C fragrance was blended into the mix.
Finally, after about 30 minutes of mixing, the organogel particles
were mixed with the final blend. Composition II was prepared
similarly as 1, except that sunflower seed oil was used in lieu of
dimethicone, and Sodium Cocoyl Isethionate was replaced with
Cocamide MEA. Also, sunflower seed oil was pre-blended with
glycerin, and isostearic acid and added at about 40 C.
[0161] Composition III was prepared slightly differently from
compositions I and II. Initially sunflower seed oil, PEG-30
Dipolyhydroxystearate, Lanolin Alcohol, cocamide MEA, petrolatum
and lauric acid were mixed together in a resin kettle at about 80 C
until a homogenous clear blend is formed. Then, glycerin was added
and at that point the blend was allowed to cool down. Subsequently,
cocamidopropyl betaine and sodium laureth sulfate were added and
mixed until the blend achieved homogenous consistency. Thereafter,
water, Guar Hydroxypropyltrimonium Chloride, citric acid, titanium
dioxide EDTA, EHDP and preservative were added. When the batch
cooled down to about 35 C, perfume was added and finally once the
final blend became homogenous, the organogel particles were added
and mixed. The viscosity of the resulting composition was about
90,000 cps.
[0162] The composition of the organogel particles was about 98%
sunflower seed oil and Polywax 500 blend at an 80:20 ratio and the
remaining 2% balance consisted of pigment colorants. The average
particle size was determined to be about 1200 microns.
[0163] Assessment of product stability for composition III was done
by visual assessment based on 2-phase separation of the base and
particles creaming to the top. Results of the product stability
evaluation revealed no signs of product separation nor accumulation
of particles on the surface of the base. The finished products were
visually stable, i.e., particles did not exhibit any signs of
rising to the top and remained uniformly distributed throughout the
base.
5 TABLE 2 % Active Level in Formula Chemical Name I II III Sodium
Lauroamphoacetate 5.6 10.0 -- Cocamidopropyl Betaine 6.0 1.9 5.7
Sodium Cocoyl Isethionate 6.5 -- -- Sodium Laureth Sulfate 6.5 13
12.3 Cocamide MEA -- 2.0 1.9 Lauric Acid -- -- 2.8 Glycerin -- --
5.7 Petrolatum -- -- 3.7 Lanolin Alcohol -- -- 0.5 Isostearic Acid
5.0 3.0 -- Sunflower Seed Oil 0.25 7.5 21.3 Dimethicone (60,000
cst) 5.0 -- -- Polyquaternium 37/Propylene Glycol 0.25 -- --
Dicaprylate/Dicaprate/PPG-1 Trideceth 6* Citric Acid 1.0 1.7 0.1
Propylene Glycol 0.5 -- -- PEG-30 Dipolyhydroxystearate -- -- 0.25
Polyquaternium 39 0.1 0.1 -- Guar Hydroxypropyltrimonium 0.1 0.25
0.7 Chloride Organogel Particle 2 2 1 Opacifier/Colorant 0.2 0.2
.about.0.1 Perfume/Preservative 1.25 1.2 1.2 Diluent/Water to 100.0
100.0 100.0 *Trade Name is Salcare SC-96
[0164] Stability findings was consistent on all products that were
stored under the following accelerated aging conditions:
[0165] 1. 51.7 C for a period of 1 month
[0166] 2. 40.5 C for a period of 1 month
[0167] 3. -9.5C/25 C--3 complete cycles where 1 cycle constitute
23.5 hours under -9.5 C followed by another 23.5 hours under 25
C
[0168] 4. 40.5 C/25 C--3 complete cycles
[0169] Stability evaluation is performed visually by comparing the
samples stored under accelerated conditions and the control sample
(stored under 25 C)
EXAMPLE 7
[0170] Organogel particles of the composition given in table 3 were
made according to the following procedure: All three samples were
spray chilled (prilled) using a pressure pot and single fluid
nozzle. The orifice diameter used in samples A and B was 0.020
inches and the orifice diameter of the nozzle used in sample C was
0.028 inches. The material was melted and the pot was heated to
keep the material above 105 degrees C. The pressure used to prill
sample A and B was 20 psi and the pressure used to prill C was 40
psi.
6TABLE 3 Sample Size, n Mean Mean PBI (number Weight to (Particle
of Break Breakage particles Mean Diameter, Particle Index, Sample
Composition tested) (microns) (g) g/mm2) A Sunflower Oil 15
742.90.mu. .+-. 40.26 3.2 g .+-. 0.68 1.9 89.96% Polywax 500 9.99%
Pigment* 0.05% B Sunflower Oil 15 773.30.mu. .+-. 64.74 12.9 g .+-.
2.6 6.9 79.92% Polywax 500 19.98% Pigment* 0.10% C Sunflower Oil 31
1184.2.mu. .+-. 193.2 0.77 g .+-. 0.51 0.2 93.54% Polywax 500 5.96%
Pigment* 0.50% Sun Chemical Light Rubine Lake)
[0171] Methods:
[0172] Particle Breakage Index (PBI)
[0173] A microscope, a microscope slide and a microscope coverslip
are required. A coverslip is placed on top of the slide. A single
particle is obtained from the sample and placed on top of the
coverslip. Using the microscope and a 10.times.objective, the
diameter of the particle is measured. After measuring the particle,
another coverslip is placed on top of the particle. Sufficient
weight is placed on top of the coverslip until the particle
ruptures. The weight required to rupture the particle is recorded.
Cross sectional area of the particle is estimated as A=.pi.r.sup.2,
where r is the radius of the particle.
[0174] Particle Stability
[0175] Particle Stability may be shown when the rate of particles
rising/floating (`creaming`) to the top is very low. This rate is
measured by Stoke equation: 1 V s = 2 r 2 g ( - ) 2 o
[0176] where
[0177] r=particle radius, m
[0178] g=acceleration due to gravity, 9.807 m/sec.sup.2
[0179] .sigma.=density of suspending medium, kg/m.sup.3
[0180] .rho.=density of particle, kg/m.sup.3
[0181] .eta..sub.o=zero shear viscosity, kg/m-sec
[0182] V.sub.s=`creaming` rate, m/sec
[0183] Perceived Organogel Particle Softness/Hardness and Ease of
Spreadability During Use.
[0184] Panelists pour organogel (about 10 to 20) particles between
the thumb and either the index and/or middle finger and press them
gently between the fingers until the particles rupture. The
panelist then rate the particles' degree of softness/hardness based
on the following rating scale--Very Hard, Hard, Just Right, Soft
and Very Soft. Then the panelists squeeze the ruptured particles in
circular motion between fingers.
[0185] To assess the particles' ease of spreadability, a small
amount of sample (about 10 to 20 particles) is poured onto the back
of one of the palms of a panelist. Then these particles are
squeezed gently, using forward and backward motions, against the
back of the palm with the middle finger and/or the index finger of
the other hand. Once the particles are completely spread over the
back of the palm, the panelist will rate them for ease of
spreadability using the following scale: Unacceptable, Slightly
Acceptable and Highly Acceptable.
[0186] T-Bar Viscosity Measurement
[0187] Scope:
[0188] This method covers the measurement of the viscosity of the
ordered liquid crystalline cleansing composition.
[0189] Apparatus:
[0190] Brookfield RVT Viscometer with Helipath Accessory;
[0191] Chuck, weight and closer assembly for T-bar attachment;
[0192] T-bar Spindle A;
[0193] Plastic cups diameter greater than 2.5 inches.
[0194] Procedure:
[0195] 1. Verify that the viscometer and the helipath stand are
level by referring to the bubble levels on the back of the
instrument.
[0196] 2. connect the chuck/closer/weight assembly to the
Viscometer (Note the left-hand coupling threads).
[0197] 3. Clean Spindle A with deionized water and pat dry with a
Kimwipe sheet. Slide the spindle in the closer and tighten.
[0198] 4. Set the rotational speed at 0.5 RPM. In case of a digital
viscometer (DV) select the % mode and press autozero with the motor
switch on.
[0199] 5. Place the product in a plastic cup with inner diameter of
greater than 2.5 inches. The height of the product in the cup
should be at least 3 inches. The temperature of the product should
be 25.degree. C.
[0200] 6. Lower the spindle into the product (.about.1/4 inches).
Set the adjustable stops of the helipath stand so that the spindle
does not touch the bottom of the plastic cup or come out of the
sample.
[0201] 7. Start the viscometer and allow the dial to make one or
two revolutions before turning on the Helipath stand. Note the dial
reading as the helipath stand passes the middle of its downward
traverse.
[0202] 8. Multiply the dial reading by a factor of 4,000 and report
the viscosity reading in cps.
[0203] While this invention has been described with respect to
particular embodiments thereof, it is apparent that numerous other
forms and modifications of the invention will be obvious to those
skilled in the art. The appended claims and this invention
generally should be construed to cover all such obvious forms and
modifications which are within the true spirit and scope of the
present invention.
* * * * *